Carrie Underwood Celebrates 15-Year Anniversary of 'American Idol' Victory

Carrie Underwood "cannot believe" it's already been 15 years since she walked away with the American Idol victory that launched her career into country superstardom. The "Cry Pretty" singer took to Twitter Monday to thank fans who had wished her a happy "Idol-versary" with a special video, sending them love to appreciating her all these years.

Calling her journey since Idol an "incredible ride," Underwood said she "couldn't have made it through" without her fans, thanking them for the "sweet video," which they dedicated to the day "your world and ours were forever changed."

Underwood has been open about how shocking her Season 4 win of American Idol was to her, saying at the Country Radio Seminar in February, "To be 1000 percent honest, I'm from the tiniest town in the world. I'd never been on a plane before. I like to sing, but lots of people like to sing. I wanted to grow up to be a famous singer, but a lot of people do. I think what I honestly thought would happen was, I would go there, and the door would shut, and I could move on with the rest of my life saying, 'Well, I tried.'"

The star added that her rise to the top of the entertainment industry all started with "one of those God moments where everything just lined up an instant," adding that she learned so much on Idol that would help her throughout her career. Her unconventional start didn't mean she didn't have the same start in the music industry as so many others do, Underwood insisted. "I grew up always wanting to sing and would sing anywhere. I'd take any opportunities. We had a band when I was a teenager, and we would go play bars in Oklahoma and Arkansas, and do car shows, fairs, and county fairs," she explained. "I did the company Christmas parties and stuff like that, too. So, it was just trying to get experience and doing what I loved, and I just always wanted to sing."

Things took a "major turn" when she tried out for American Idol, of course. "I think at that point I was at a time in my life where it was like, 'Grow up' ... I had to make some kind of decision, and I was about to graduate from university, and it was time to grow up, get a job, right?" Underwood would go on to win Season 4 of Idol, beating out runner-up Bo Bice.